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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Metodologia de análise de impacto em segurança crítica da automação das tarefas do controlador de tráfego aéreo da torre de controle de aeródromo. / Impact analysis methodology for safety of aerodrome control tower air traffic controllers tasks automation.

Dirickson, Yuri Maximilian Rottner 16 May 2016 (has links)
Com o crescimento contínuo na utilização da aviação como meio de transporte de pessoas e carga, o sistema de gerenciamento de tráfego aéreo (ATM) está no limite de sua capacidade. Para lidar com esse problema, a Organização de Aviação Civil Internacional (OACI), junto com diversos países membros, desenvolveu um novo conceito de ATM chamado CNS/ATM, composto de uma série de melhorias tecnológicas para melhorar a capacidade e desempenho do sistema, onde muitas dessas melhorias são automatizações de tarefas de operadores humanos, pilotos e controladores de tráfego aéreo (ATCo). Com o tempo percebeu-se que apenas avanços tecnológicos não seriam o suficiente, que era necessário uma integração maior entre todos os sistemas ATM, que garantisse uma interoperabilidade entre os sistemas. Portanto, o conceito CNS/ATM evoluiu para o conceito ATM Global, onde o planejamento de modernização se dará de forma integrada e global, incluindo muitas das melhorias previstas no conceito CNS/ATM. Essa mudança de paradigma faz surgir diversas questões de como essas mudanças impactarão no atual sistema, do ponto de vista econômico, ambiental, desempenho e segurança. Para entender os perigos envolvidos na execução dessas novas tarefas, utilizam-se diversas técnicas e modelos clássicas como a Análise de Árvores de Falhas (FTA) ou a Análise de Árvore de Erros (ETA). Essas técnicas tradicionais consideram que acidentes são causados por uma sequência de eventos de falha, todos com uma relação de causa e efeito. Essa suposição não é considerada mais suficiente para entender como acidentes acontecem nos sistemas mais atuais, onde cada vez mais eles se tornam mais complexos e mais dependentes da interação com softwares. Para lidar com essa dificuldade foram criados alguns modelos para entender acidentes utilizando a teoria de sistemas, como exemplo o Systems-Theoretic Accident Model and Proccesses (STAMP). Diversos estudo mostram que esses modelos ou métodos são capazes de representar problemas na estrutura de controle que as técnicas mais tradicionais não conseguem, inclusive incluindo fatores organizacionais na sua representação. Considerando todos esses fatos, este trabalho de investigação científica propõe uma metodologia de análise de impacto em segurança crítica da automação das tarefas dos ATCo de uma torre de comando de aeródromo (TWR). A metodologia consiste na modelagem dos perigos e acidentes envolvidas nas tarefas do ATCo da TWR utilizando o modelo sistêmico STAMP) depois na análise subsequente dos cenários antes da automação e depois da automação utilizando a técnica Systems-Theoretic Proccess Analysis (STPA), criada a partir do STAMP, para levantar os fatores causais de perigos e seus requisitos de segurança em cada cenário, de forma a ser possível obter uma comparação do que foi modificado com a automação proposta das tarefas. Para validar a metodologia, foi analisada uma tarefa do ATCo da TWR como exemplo. Espera-se obter com a metodologia proposta uma forma mais objetiva e sistêmica de obter o possível impacto em termos de segurança crítica da automação de uma tarefa específica, sendo possível então determinar qual a melhor forma de se pensar essa automação no contexto do ATCo, podendo assim contribuir para a modernização segura do sistema ATM. / With the increasing growth of aviation as mode of transportation for people and cargo, the Air Traffic Management (ATM) system is on its limits. In order to cope with that, the International Civil Aviation Organization (ICAO), together with country members, developed a new ATM concept called CNS/ATM, bearing several technological improvements with the objective of enhancing capacity and performance of the system, where many of these improvements are automated tasks of human operators, pilots and air traffic controllers (ATCo). In time, it was seen that technological improvements were not enough it was necessary a greater integration between all ATM systems, which would guarantee an interoperability between them. Therefore, the CNS/ATM concept evolved to a Global ATM concept, in which the modernization plan would occur globally and integrated, including many of the improvements of the CNS/ATM concept. This paradigm shift raised several questions on how these changes would affect in the actual system from an economic, environmental, performance and safety points of view. To understand the hazards of the new tasks, several traditional techniques and models are used, like Fault Tree Analysis (FTA) and Error Tree Analysis (ETA). These traditional techniques see accidents because of a chain of failure events, all with an effect-cause relation. This assumption is no longer considered enough in order to understand how accidents occur in actual systems, which became more complexes and more software dependents. To cope with this difficulty, other models were created to understand accidents using systems theory, for example the Systems-Theoretic Accident Model and Processes (STAMP). Several studies show that these models or methods are capable of finding more problems in control structure that the traditional techniques, including organizational factors. Considering all the facts, this scientific investigation propose a methodology for analysis of the impact on safety for the automation of ATCo from Control Tower (TWR) tasks. This methodology consists in modeling the accidents and hazards of the TWR ATCo tasks using STAMP. Then the Systems-Theoretic Process Analysis (STPA) technique, created for STAMP, is used to gather all causal factors for hazards and its safety requirements in each scenario, in order to compare what changed with the automation of tasks. The objective of proposed methodology is to obtain a systemic and objective way of finding the possible impact on safety from the automation of a specific task, enabling the possibility of determining the best way of designing the automation in the context of ATCo, contributing to the safe modernization of ATM system.
2

Metodologia de análise de impacto em segurança crítica da automação das tarefas do controlador de tráfego aéreo da torre de controle de aeródromo. / Impact analysis methodology for safety of aerodrome control tower air traffic controllers tasks automation.

Yuri Maximilian Rottner Dirickson 16 May 2016 (has links)
Com o crescimento contínuo na utilização da aviação como meio de transporte de pessoas e carga, o sistema de gerenciamento de tráfego aéreo (ATM) está no limite de sua capacidade. Para lidar com esse problema, a Organização de Aviação Civil Internacional (OACI), junto com diversos países membros, desenvolveu um novo conceito de ATM chamado CNS/ATM, composto de uma série de melhorias tecnológicas para melhorar a capacidade e desempenho do sistema, onde muitas dessas melhorias são automatizações de tarefas de operadores humanos, pilotos e controladores de tráfego aéreo (ATCo). Com o tempo percebeu-se que apenas avanços tecnológicos não seriam o suficiente, que era necessário uma integração maior entre todos os sistemas ATM, que garantisse uma interoperabilidade entre os sistemas. Portanto, o conceito CNS/ATM evoluiu para o conceito ATM Global, onde o planejamento de modernização se dará de forma integrada e global, incluindo muitas das melhorias previstas no conceito CNS/ATM. Essa mudança de paradigma faz surgir diversas questões de como essas mudanças impactarão no atual sistema, do ponto de vista econômico, ambiental, desempenho e segurança. Para entender os perigos envolvidos na execução dessas novas tarefas, utilizam-se diversas técnicas e modelos clássicas como a Análise de Árvores de Falhas (FTA) ou a Análise de Árvore de Erros (ETA). Essas técnicas tradicionais consideram que acidentes são causados por uma sequência de eventos de falha, todos com uma relação de causa e efeito. Essa suposição não é considerada mais suficiente para entender como acidentes acontecem nos sistemas mais atuais, onde cada vez mais eles se tornam mais complexos e mais dependentes da interação com softwares. Para lidar com essa dificuldade foram criados alguns modelos para entender acidentes utilizando a teoria de sistemas, como exemplo o Systems-Theoretic Accident Model and Proccesses (STAMP). Diversos estudo mostram que esses modelos ou métodos são capazes de representar problemas na estrutura de controle que as técnicas mais tradicionais não conseguem, inclusive incluindo fatores organizacionais na sua representação. Considerando todos esses fatos, este trabalho de investigação científica propõe uma metodologia de análise de impacto em segurança crítica da automação das tarefas dos ATCo de uma torre de comando de aeródromo (TWR). A metodologia consiste na modelagem dos perigos e acidentes envolvidas nas tarefas do ATCo da TWR utilizando o modelo sistêmico STAMP) depois na análise subsequente dos cenários antes da automação e depois da automação utilizando a técnica Systems-Theoretic Proccess Analysis (STPA), criada a partir do STAMP, para levantar os fatores causais de perigos e seus requisitos de segurança em cada cenário, de forma a ser possível obter uma comparação do que foi modificado com a automação proposta das tarefas. Para validar a metodologia, foi analisada uma tarefa do ATCo da TWR como exemplo. Espera-se obter com a metodologia proposta uma forma mais objetiva e sistêmica de obter o possível impacto em termos de segurança crítica da automação de uma tarefa específica, sendo possível então determinar qual a melhor forma de se pensar essa automação no contexto do ATCo, podendo assim contribuir para a modernização segura do sistema ATM. / With the increasing growth of aviation as mode of transportation for people and cargo, the Air Traffic Management (ATM) system is on its limits. In order to cope with that, the International Civil Aviation Organization (ICAO), together with country members, developed a new ATM concept called CNS/ATM, bearing several technological improvements with the objective of enhancing capacity and performance of the system, where many of these improvements are automated tasks of human operators, pilots and air traffic controllers (ATCo). In time, it was seen that technological improvements were not enough it was necessary a greater integration between all ATM systems, which would guarantee an interoperability between them. Therefore, the CNS/ATM concept evolved to a Global ATM concept, in which the modernization plan would occur globally and integrated, including many of the improvements of the CNS/ATM concept. This paradigm shift raised several questions on how these changes would affect in the actual system from an economic, environmental, performance and safety points of view. To understand the hazards of the new tasks, several traditional techniques and models are used, like Fault Tree Analysis (FTA) and Error Tree Analysis (ETA). These traditional techniques see accidents because of a chain of failure events, all with an effect-cause relation. This assumption is no longer considered enough in order to understand how accidents occur in actual systems, which became more complexes and more software dependents. To cope with this difficulty, other models were created to understand accidents using systems theory, for example the Systems-Theoretic Accident Model and Processes (STAMP). Several studies show that these models or methods are capable of finding more problems in control structure that the traditional techniques, including organizational factors. Considering all the facts, this scientific investigation propose a methodology for analysis of the impact on safety for the automation of ATCo from Control Tower (TWR) tasks. This methodology consists in modeling the accidents and hazards of the TWR ATCo tasks using STAMP. Then the Systems-Theoretic Process Analysis (STPA) technique, created for STAMP, is used to gather all causal factors for hazards and its safety requirements in each scenario, in order to compare what changed with the automation of tasks. The objective of proposed methodology is to obtain a systemic and objective way of finding the possible impact on safety from the automation of a specific task, enabling the possibility of determining the best way of designing the automation in the context of ATCo, contributing to the safe modernization of ATM system.
3

UWB-TWR performance comparison in a hybrid node network

Sundin, Oskar January 2021 (has links)
This thesis investigated the performance of a positioning system that utilised UWB technology where devices regularly shifts between acting as an initiator and as a responder for distance measurements between each other. The goal was to investigate existing positional techniques and to implement a novel network where devices initiates and responds to distance measurement exchanges. Additionally, the intention of this positioning system is to prevent severe work accidents and reduce vehicle congestion costing lives, money and time in industrial workplace environments. In the thesis, two ranging techniques, skew-aware single-sided two-way ranging (SASS-TWR) and asymmetric double-sided two-way ranging (ADS-TWR) were compared to each other as well as two MAC protocols, CSMA/CA and the token ring protocol. Results showed that SASS-TWR and ADS-TWR had similar precision, but SASS-TWR was faster, making it the preferred option in a positioning system. For the MAC protocols, simulations showed that the token ring protocol outperformed CSMA/CA but had a major flaw in its current implementation with the lack of recoverability in cases where devices in the network stops functioning or leaves. The conclusion is that both ranging techniques are viable options, and for the MAC protocols, CSMA/CA could be used but lacks scalability. The token ring protocol outperformed CSMA/CA in speed and scalability but requires improvements in recoverability before it could be used in a positional system intended for the industrial workplace.
4

Production and Evaluation of Rapid Tooling for Electric Discharge Machining using Electroforming and Spray Metal Deposition Techniques

Blom, Ricky J January 2005 (has links)
To survive in today's manufacturing environments companies must push the standards of accuracy and speed to the highest levels possible. Electro Discharge Machining (EDM) has been used for over 50 years and recent developments have seen the use of EDM become much more viable. The goal of this research is to produce and evaluate electrodes produced by different manufacturing methods. The use of electroforming and spray-metal deposition has only recently become viable methods of producing usable rapid tooling components. The speed and accuracy as well as the cost of manufacture play a vital role in the tool and mould manufacturing process. Electroforming and spray-metal deposition offer an alternate option to traditional machining of electrodes. Electroforming is one method of producing electrodes for EDM. The fact that electroforming can be used to produce multiple electrodes simultaneously gives it the advantage of saving on costs when multiple electrodes are needed. Spray-metal deposition offers another alternative that is much cheaper and relatively faster to manufacture. The used of these non-traditional manufacturing methods in this research are compared to the performance of traditional solid electrodes in terms of machining time, material removal rate, tool wear rates and surface roughness at several standard machining settings. The results of this research are presented in this thesis along with conclusions and comments on the performance of the different methods of electrode manufacture. The major findings of the research include the solid electrodes performed better than the electroformed electrodes in Material Removal Rate (MRR), Tool Wear Rate (TWR), and Surface Roughness (Ra) at all machine settings. However it was found that the production cost of the solid electrodes was six times that of the electroformed electrodes. The production of spray metal electrodes was unsuccessful. The electrode shell walls were not an even thickness and the backing material broke through the shell making them unusable. It is concluded that with further refinements and research, electroforming and spray metal processes will become an extremely competitive method in electrode manufacture and other rapid tooling processes.
5

A Study of Adobe Wall Moisture Profiles and the Resulting Effects on Matched Illumination Waveforms in Through-The-Wall Radar Applications

Price, Steven Ryan 14 August 2015 (has links)
In this dissertation, methods utilizing matched illumination theory to optimally design waveforms for enhanced target detection and identification in the context of through-the-wall radar (TWR) are explored. The accuracy of assumptions made in the waveform design process is evaluated through simulation. Additionally, the moisture profile of an adobe wall is investigated, and it is shown that the moisture profile of the wall will introduce significant variations in the matched illumination waveforms and subsequently, affect the resulting ability of the radar system to correctly identify and detect a target behind the wall. Experimental measurements of adobe wall moisture and corresponding dielectric properties confirms the need for accurate moisture profile information when designing radar waveforms which enhance signal-to-interference-plus-noise ratio (SINR) through use of matched illumination waveforms on the wall/target scenario. Furthermore, an evaluation of the ability to produce an optimal, matched illumination waveform for transmission using simple, common radar systems is undertaken and radar performance is evaluated.
6

Investigating Novel Electrode Design Methodologies for Faster Slotting in Silicon Using Die Sink EDM

Karim, Mahmud Anjir 21 July 2023 (has links)
No description available.

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